Marking pen



FIG. 1 is a front elevational view of a marking pen showing my new design;

FIG. 2 is a rear elevational view;

FIG. 3 is a left side elevational view;

FIG. 4 is a right side elevational view;

FIG. 5 is a top plan view;

FIG. 6 is a bottom plan view;

FIG. 7 is a top perspective view; and,

FIG. 8 is a top perspective view in an exploded condition.

FIGS. 1 through 4 and 7 and 8 have been shaded to indicate color contrast. 

The ornamental design for a marking pen, as shown and described. 